STUDY OF MATERIALS AND WELDING USED IN THE CONSTRUCTION OF RACKS FOR STORAGE OF FUEL ELEMENTS AT NUCLEAR PLANTS

This paper showed the technological innovations and the necessary requirements for the welding of ASTM A240 TP316L Austenitic Stainless Steel in the construction of racks used in the storage of Fuel Elements inside nuclear power plants. It presents the development of welding processes using coated electrode, SMAW and as addition metal rods EAS 2-IG / ER 308L. This study is divided into two stages, the preparation of technical documentation and the development of methods and manufacturing processes used in the qualification of welding processes. A sequence was outlined based on real situations used by nuclear component manufacturing companies, meeting the physical and mechanical properties required by the nuclear classification standards and their regulations. The results showed that the welding processes were satisfactory, that the destructive and non-destructive tests showed that there was no discontinuity in the surface and defects in the volume of the welding and that, in the present study, safety in the project for the operation of a Nuclear Power Plant was demonstrated.

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Radiation shielding structures : Concepts, behaviour and the role of the heavy weight concrete as a shielding material - Rewiev

Concrete Structures ◽

10.32970/cs.2020.1.4 ◽

2020 ◽

Vol 21 ◽

pp. 24-30

Author(s):

Suha Ismail Ahmed Ali ◽

Éva Lublóy

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Building Materials ◽

Physical And Mechanical Properties ◽

Cost Effective ◽

Radiation Shielding ◽

Radiation Emission ◽

Neutron Shielding ◽

Heavy Weight ◽

Industrial Buildings

The construction of radiation shielding buildings still developed. Application of ionizing radiations became necessary for different reasons, like electricity generation, industry, medical (therapy treatment), agriculture, and scientific research. Different countries all over the world moving toward energy saving, besides growing the demand for using radiation in several aspects. Nuclear power plants, healthcare buildings, industrial buildings, and aerospace are the main neutrons and gamma shielding buildings. Special design and building materials are required to enhance safety and reduce the risk of radiation emission. Radiation shielding, strength, fire resistance, and durability are the most important properties, cost-effective and environmentally friendly are coming next. Heavy-weight concrete (HWC) is used widely in neutron shielding materials due to its cost-effectiveness and worthy physical and mechanical properties. This paper aims to give an overview of nuclear buildings, their application, and behaviour under different radiations. Also to review the heavy-weight concrete and heavy aggregate and their important role in developing the neutrons shielding materials. Conclusions showed there are still some gaps in improving the heavy-weight concrete (HWC) properties.

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Steady-State Thermal-Hydraulic Analysis of a Particle-Bedded Boiling Water Reactor

Volume 4: Codes, Standards, Licensing and Regulatory Issues; Student Paper Competition ◽

10.1115/icone17-75050 ◽

2009 ◽

Author(s):

Xiaoyu Cai ◽

Suizheng Qiu ◽

Guanghui Su ◽

Changyou Zhao

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Superheated Steam ◽

Nuclear Reactor ◽

Hydraulic Analysis ◽

Light Water ◽

Safety Systems ◽

Fuel Elements ◽

Thermal Hydraulic Analysis

The current Light Water Reactors both BWR and PWR have extensive nuclear reactor safety systems, which provide safe and economical operation of Nuclear Power Plants. During about forty years of operation history the safety systems of Nuclear Power Plants have been upgraded in an evolutionary manner. The cost of safety systems, including large containments, is really high due to a capital cost and a long construction period. These conditions together with a low efficiency of steam cycle for LWR create problems to build new power plants in the USA and in the Europe. An advanced Boiling Water Reactor concept with micro-fuel elements (MFE) and superheated steam promises a radical enhancement of safety and improvement of economy of Nuclear Power Plants. In this paper, a new type of nuclear reactor is presented that consists of a steel-walled tube filled with millions of TRISO-coated fuel particles (Micro-Fuel Elements, MFE) directly cooled by a light-water coolant-moderator. Water is used as coolant that flows from bottom to top through the tube, thereby fluidizing the particle bed, and the moderator water flows in the reverse direction out of the tube. The fuel consists of spheres of about 2.5 mm diameter of UO2 with several coatings of different carbonaceous materials. The external coating of steam cycle the particles is silicon carbide (SiC), manufactured with chemical vapor deposit (CVD) technology. Steady-State Thermal-Hydraulic Analysis aims at providing heat transport capability which can match with the heat generated by the core, so as to provide a set of thermal hydraulic parameters of the primary loop. So the temperature distribution and the pressure losses along the direction of flow are calculated for equilibrium core in this paper. The calculation not only includes the liquid region, but the two phase region and the superheated steam region. The temperature distribution includes both the temperature parameters of micro-fuel elements and the coolant. The results show that the maximum fuel temperature is much lower than the limitation and the flow distribution can meet the cooling requirement in the reactor core.

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Model of the Deposition of Colloidal Crud Particles on the Fuel Elements of Nuclear Power Plants

Nuclear Science and Engineering ◽

10.13182/nse83-a17718 ◽

1983 ◽

Vol 84 (2) ◽

pp. 120-130 ◽

Cited By ~ 8

Author(s):

Guillermo A. Urrutia ◽

Susana I. Passaggio ◽

A. J. G. Maroto ◽

Miguel A. Blesa

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Fuel Elements

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Structural Integrity Assessment of Doel 3 and Tihange 2 RPVs Affected by Hydrogen Flakes: Refined X-FEM Analyses

Volume 1A: Codes and Standards ◽

10.1115/pvp2016-63766 ◽

2016 ◽

Author(s):

Pierre Dulieu ◽

Valéry Lacroix

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Extended Finite Element Method ◽

Structural Integrity ◽

Pressure Vessels ◽

Extended Finite Element ◽

Integrity Assessment ◽

Safety Case ◽

Component Manufacturing ◽

Reactor Pressure

During the 2012 outage at Doel 3 and Tihange 2 Nuclear Power Plants, specific ultrasonic in-service inspections revealed a large number of quasi-laminar indications in the base metal of the reactor pressure vessels, mainly in the lower and upper core shells. The observed indications could subsequently be attributed to hydrogen flaking induced during the component manufacturing process. As a consequence, a Flaw Acceptability Assessment had to be performed as a part of the Safety Case demonstrating the fitness-for-service of these units. In that framework, detailed analyses using eXtended Finite Element Method were conducted to model the specific character of hydrogen flakes. Their quasi-laminar orientation as well as their high density required setting up 3D multi-flaws model accounting for flaw interaction. These calculations highlighted that even the most penalizing flaw configurations are harmless in terms of structural integrity despite the consideration of higher degradation of irradiated material toughness.

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Polymeric seal degradation in nuclear power plants: Determination of physical and mechanical properties

Journal of Applied Polymer Science ◽

10.1002/app.45814 ◽

2017 ◽

Vol 135 (7) ◽

pp. 45814 ◽

Cited By ~ 1

Author(s):

Christopher P. Porter ◽

James P. Bezzina ◽

Francis Clegg ◽

Mark D. Ogden

Keyword(s):

Mechanical Properties ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Physical And Mechanical Properties

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Isolation of nuclear power plants from earthquake attack

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.9.4.199-204 ◽

1976 ◽

Vol 9 (4) ◽

pp. 199-204

Author(s):

R. I. Skinner ◽

R. G. Tyler ◽

S. B. Hodder

Keyword(s):

Power Plant ◽

Nuclear Power ◽

Power Plants ◽

Base Isolation ◽

Isolation System ◽

Base Isolation System ◽

Critical Components ◽

Fuel Elements ◽

Control Rods ◽

Very High

The analysis of one-mass and two-mass models indicates that the earthquake-generated horizontal forces and deformations of the main structures of a nuclear power plant can be reduced by a factor of about ten times by mounting the overall power plant building on a recently developed base-isolation system. The very high forces which the ‘resonant appendage‘ effect may induce in some critical components (such  as fuel elements, control rods and essential piping) may be reduced by a factor of 40 or more times by the isolation system. The parameters of  the isolation system have been chosen as appropriate to the level of protection which should be provided for a nuclear plant in a seismically active area. Consideration is given to flexible mounts and dampers suitable for such an isolator.

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Quantity and Management of Spent Fuel From Prototype and Research Reactors in Germany

Volume 1: Low/Intermediate-Level Radioactive Waste Management; Spent Fuel, Fissile Material, Transuranic and High-Level Radioactive Waste Management ◽

10.1115/icem2013-96040 ◽

2013 ◽

Author(s):

Sabine Dörr ◽

Wilhelm Bollingerfehr ◽

Wolfgang Filbert ◽

Marion Tholen

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Storage Management ◽

Ministry Of Education ◽

Spent Fuel ◽

Research Reactors ◽

Identification Number ◽

Current State ◽

Fuel Elements

Within the scope of an R&D project (project identification number FKZ 02 S 8679) sponsored by BMBF (Federal Ministry of Education and Research), the current state of storage and management of fuel elements from prototype and research reactors was established, and an approach for their future storage/management was developed. The spent fuels from prototype and research reactors in Germany that require disposal were specified and were described in regard to their repository-relevant characteristics. As there are currently no casks licensed for disposal in Germany, descriptions of casks that were considered to be suitable were provided. Based on the information provided on the spent fuel from prototype and research reactors and the potential casks, a technical disposal concept was developed. In this context, concepts to integrate the spent fuel from prototype and research reactors into existing disposal concepts for spent fuel from German nuclear power plants and for waste from reprocessing were developed for salt and clay formations.

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ANALYSIS OF RESIDUAL STRESS FOR NARROW GAP WELDING USING FINITE ELEMENT METHOD

International Journal of Modern Physics B ◽

10.1142/s0217979210065659 ◽

2010 ◽

Vol 24 (15n16) ◽

pp. 2797-2802 ◽

Cited By ~ 1

Author(s):

CHOON YEOL LEE ◽

JAE KEUN HWANG ◽

JOON WOO BAE

Keyword(s):

Finite Element Method ◽

Residual Stress ◽

Finite Element ◽

Nuclear Power ◽

Power Plants ◽

Large Diameter ◽

Narrow Gap ◽

Narrow Gap Welding ◽

Welding Processes ◽

Element Method

Reactor coolant loop (RCL) pipes circulating the heat generated in a nuclear power plant consist of so large diameter pipes that the installation of these pipes is one of the major construction processes. Conventionally, a shield metal arc welding (SMAW) process has been mainly used in RCL piping installations, which sometimes caused severe deformations, dislocation of main equipments and various other complications due to excessive heat input in welding processes. Hence, automation of the work of welding is required and narrow-gap welding (NGW) process is being reviewed for new nuclear power plants as an alternative method of welding. In this study, transient heat transfer and thermo-elastic-plastic analyses have been performed for the residual stress distribution on the narrow gap weldment of RCL by finite element method under various conditions including surface heat flux and temperature dependent thermo-physical properties.

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The Issue of Underground Depositing of High Radioactive Waste

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.722.59 ◽

2016 ◽

Vol 722 ◽

pp. 59-65

Author(s):

Markéta Kočová ◽

Zdeňka Říhová ◽

Jan Zatloukal

Keyword(s):

Radioactive Waste ◽

Nuclear Power ◽

Power Plants ◽

High Level Waste ◽

Spent Fuel ◽

High Level Radioactive Waste ◽

Medium Level ◽

Long Time ◽

High Level ◽

Fuel Elements

Nowadays manipulation and depositing of high-level radioactive waste has become the most important issue, which needs to be solved. High-level radioactive waste consists mainly of spent fuel elements from nuclear power plants, which cannot be deposited for long time in surface repositories in the same way as it is possible in case of low and medium level radioactive waste. The most effective and safe solution in longer time horizon seems to be deep geological repository of high level waste. In this process of deposition, large amount of specific conditions needs to be taken into account while designing the whole underground complex, because the materials and structures must fulfil all necessary requirements. Then adequate safety will be ensured.

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